300mm f2.8....A decent walkabout lens? (1 Viewer)

I got a similar shot of Whitethroat last week with the 400/5.6 and 1.4tc, even at 560mm it is a heavy crop but the lens lets you crop heavy (even 100%) and still get good IQ for web use.

These lenses take cracking shots.
The reason I am thinking the 300 f2.8 is, in the UK, we don't get bright sunny days every day of the week.
I was just thinking of the good old British low light weather conditions.
Or am I barking up the wrong tree with this lens.....or just barking?

Nice Whitethroats Gents

Roy C said:

I got a similar shot of Whitethroat last week with the 400/5.6 and 1.4tc, even at 560mm it is a heavy crop but the lens lets you crop heavy (even 100%) and still get good IQ for web use.

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That's a nice shot Roy, fab little birds.

Gaz Shilton said:

These lenses take cracking shots.
The reason I am thinking the 300 f2.8 is, in the UK, we don't get bright sunny days every day of the week.
I was just thinking of the good old British low light weather conditions.
Or am I barking up the wrong tree with this lens.....or just barking?

Nice Whitethroats Gents

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You not barking mad. In fact your suggestion demonstrates practical thinking.

Gaz Shilton said:

These lenses take cracking shots.
The reason I am thinking the 300 f2.8 is, in the UK, we don't get bright sunny days every day of the week.
I was just thinking of the good old British low light weather conditions.
Or am I barking up the wrong tree with this lens.....or just barking?

Nice Whitethroats Gents

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You don't have to worry too much about the light conditions when choosing a lens these days as the modern DSLR cameras are very good at shooting at high iso without Noise. All should be good at iso 400, some at iso 800 and a few even at iso 1600 ( eg Nikon D3).
The speed of the lens does play a part in bird flight photography though. If you want to photograph ducks in flight then the faster the lens the better. But you'll find that most of the time you'll have a 1.4x tele on so you'll be at least at f4. The only time I use a straight 300 mm lens is for egrets and herons. The closer you get to a bird the faster they move , so longer is better.
Neil.

This is kind of tangential to the thread but is it possible that a 'faster' lens, i.e. one with a greater maximum aperture, isn't always the best choice?

A 'faster' lens, e.g f/2.8 rather than f/4, is inevitably bigger, heavier and more expensive and with the aperture fully open will have a shallower depth of field than the 'slower' lens. Image quality, particularly of moving subjects, might then depend on how light, mobile and stable the lens is when used in the hand and on how much of the subject is in focus across the field of view.
I'd be interested in people's views, particularly with regard to depth of field. I'm here to learn, not just have my prejudices confirmed.

Mike

Carlton said:

This is kind of tangential to the thread but is it possible that a 'faster' lens, i.e. one with a greater maximum aperture, isn't always the best choice?

A 'faster' lens, e.g f/2.8 rather than f/4, is inevitably bigger, heavier and more expensive and with the aperture fully open will have a shallower depth of field than the 'slower' lens. Image quality, particularly of moving subjects, might then depend on how light, mobile and stable the lens is when used in the hand and on how much of the subject is in focus across the field of view.
I'd be interested in people's views, particularly with regard to depth of field. I'm here to learn, not just have my prejudices confirmed.

Mike

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Hi,

I use f/2.8 on my 70-200 IS, but only for static birds which can work out very nice. But, for BIF i will use f/5.6 because you need more DOF to keep the bird in focus.

I'm a fool for shallow DOF, so i keep thinking of the 300/f2.8, but it is heavy to walk around with.


Regards,

Rob

@ Mike....

You can focus with an f/2.8 lens faster and more accurately than with a slower lens. You'll also have a brighter viewfinder and may find manual focus easier too. There is nothing to say you can't stop down for the shot itself. DOF aside, if the light is low you have options on shutter speed and/or ISO that an f/5.6 lens does not afford you.

A 300/2.8 can serve many purposes other than a dedicated birding/wildlife lens. It could have a place at weddings and sports events, for example. The ability to open up wide to f/2.8 give you the choice to purposely have a shallow DOF.

At relatively low incremental cost you can turn that 300/2.8 into quite a flexible package with the addition of a couple of teleconverters - a 420/4 or a 600/5.6 and still under £4k for all those options. If you were to buy a 500/4 or 600/4 it would cost you a sh!tload more money. It might be the master of one trade but it might be of limited use for those of us who do shoot things other than birds. Of course, you can add telecons to those too and get even more reach, especially if shooting with a 1 series, but I think really it is horses for courses. Would you find 300-600/2.8-5.6 a better range the 500-700/4-5.6 etc.?

As for the weight thing, up to a point more mass means more inertia and more inertia means less shake. I hear people can handhold a 500/4 but a tripod is probably better, so at those lengths you're probably into tripod territory anyway. If 300 is too short you have options to extend or crop. If 500 is too long then you will have to ask the bird to hang on while you take a few steps back, or take a panorama series and stitch them together (Joke!).

I have to say I was thinking a 500/4 might be my next lens, but at the moment, if I was forced to make a choice today, it would be the 300/2.8. I think I will continue to feel that way but I'm not willing to pay today's prices so the point is currently moot. I'll wait till exchange rates move back in our favour.

Thanks for the interesting replies. My budget doesn't stretch to £3.5K for the 300mm f/2.8 when I have so many other outgoings - wife, kids, nice bikes...
I guess my point was that a one stop slower lens, e.g. the 300mm f/4, has the advantages of considerably less expense and, being much lighter, is easier to hand hold. The extra stop can be regained by pushing up the ISO by a single point, which is hardly noticeable in reasonable light.. Is the extra stop really worth the extra cost, particularly when it also reduces the depth of field?
Perhaps there isn't a right answer but it makes for an interesting discussion.
Mike

Carlton said:

Thanks for the interesting replies. My budget doesn't stretch to £3.5K for the 300mm f/2.8 when I have so many other outgoings - wife, kids, nice bikes...
I guess my point was that a one stop slower lens, e.g. the 300mm f/4, has the advantages of considerably less expense and, being much lighter, is easier to hand hold. The extra stop can be regained by pushing up the ISO by a single point, which is hardly noticeable in reasonable light.. Is the extra stop really worth the extra cost, particularly when it also reduces the depth of field?
Perhaps there isn't a right answer but it makes for an interesting discussion.
Mike

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Mike, I think a lot of bird photographers are intrested in the lens because you can get to 600mm at f5.6 which still gives you AF on a 1.6 crop camera. whereas with the f4 you can only get to 420mm. In general the lens takes converters possibly better than any other Canon telephoto. Also one stop means that you are getting twice the amount of light which can be very handy in low light.

Pushing up the ISO can't make an f/4 lens focus like an f/2.8 lens. f/2.8 is a significant cutoff point in AF speed and accuracy. According to documentation I've seen, at f/2.8 and faster a camera should be able to focus to within 1/3 DOF. Slower than f/2.8 the AF is only specced to an accuracy of "somewhere" within the DOF.

At a distance of 20m a 300mm f/2.8 lens at f/2.8 will give you a DOF of +/-23cm. The focus accuracy should be off by no more than 7-8cm, pretty much guaranteeing a sharp subject and a safe margin both in front of and behind the focused point.

At a distance of 20m a 300mm f/4 lens at f/4 will give you a DOF of +/-33cm. Your focus could be off by as much as 33cm, meaning a significant portion of your subject may be completely outside the DOF, even if the area you focused on is still within the DOF.

If you used the f/2.8 lens stopped down to f/4 you would gain the f/2.8 AF precision of +/- 7cm and still benefit from the larger DOF of +/-33cm that f/4 offers.

tdodd said:

If you used the f/2.8 lens stopped down to f/4 you would gain the f/2.8 AF precision of +/- 7cm and still benefit from the larger DOF of +/-33cm that f/4 offers.

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G'day Tim,

Thanks for this interesting explanation. But how does this work if you put a 1.4 or 2x converter on a 300/f2.8?.

Regards,

Robert

Adding a teleconverter negates the advantage since the longer focal length loses you a stop (or two) of aperture. However, an f/2.8 lens plus a 2X still keeps you at the next magical aperture value of f/5.6, which means you retain AF on all bodies. Stick the 2X onto an f/4 lens and you'll end up at f/8, which is well outside spec for all but the 1 series bodies, and even with them you are limited to centre point AF only. I imagine the expansion points are also disabled at f/8.

All of this information is invaluable for decision making.
It seems my mind is made up with this lens.
Take the plunge and forget about the 'what ifs'.
The 300 f2.8 is the way to go...for me anyway.

Thank you

I took some shots today of cyclists. Yes, cyclists! To be more accurate, it was a time trial. Riders were approaching at around 30 mph. I had a 300mm F4 IS lens on a monopod and Canon 400D body.
I got about 5 very good sharp shots out of 300. The reason was that the focus was lagging behind, and that the 400D is only capable of 3 frames/second on servo focus. The ISO was 800.

This kept me thinking. How much would a good body improve the quality of the pictures, and how much would a good lens improve them?

For the lens, winning 1 F-stop could mean getting back to ISO400, which would result of 4 times sharper pixels. Or I could just get a faster focus (sometimes it was too slow, especially when riders were very close and I was panning). Or I could have half the shutter time.

For the body, if I had a 50D, I could reach 6fps, which is double. So when in focus, the camera would take the shot double as fast as with the 400D. Since riders were approaching me with around 15m/second, 0.18 seconds results in the focus lagging about 2.5 meters behind. That is more than the depth of field I had at F4. Also, the 50D has more pixels (15MP) and better algorithms to keep noise to a low level, and higher ISO values are possible.

What would improve the most? New lens or new body?
I think the best would be a new body. A new lens would only be a real improvement if combined with a good body!

Any comment about my thinkings is welcome ;-)

here are the pictures:
http://appelflap.ocp-s.tudelft.nl/gallery/index.php/Wielrennen/WTOS/(2009-06-24) WTOS 10km
All of them are downloadable JPG and not photoshopped.

Temmie, I would think that out of a rather modest entry level body and an "L" grade prime lens with lighter glassware than the 300/2.8 it is more than likely that the body is holding you back more than the glass. Having used neither one I am unable to be sure, but it seems a strong bet to me. By the way, when Canon was describing the focus improvements in the 40D over the 30D in the 40D White Paper they picked the 300/2.8 as their lens of choice for their example, which, if I may quote, said....

Compared to the EOS 30D, the EOS 40D’s focusing calculation speed is 1.3 times faster, and the AF data-processing time is shorter. Predictive AF can track a subject approaching at 50 kph/31 mph up to about 26.2 ft./8m away with an EF 300mm f/2.8L IS USM lens.

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Now, they chose to cite the f/2.8 version, but I imagine the f/4 is no slouch either. In fact, the f/4 lens may possibly be able to focus faster, due to lighter glassware, (immesnsely specualtive there) but the f/4 aperture means the camera has less solid data to work with than with the f/2.8 lens, and thus in practice the f/2.8 lens turns in finer results.

If we look at the comments made in DP Reviews review of the 400D, regarding the 400D's AF system, they said....

Nine-point Auto Focus sensor
One criticism of the EOS 300D/350D was auto-focus, Canon has decided to bite the bullet and simply installed the considerably better nine point AF sensor from the EOS 30D in the EOS 400D. This affords both faster, more accurate focusing as well as center point AF which is compatible with F2.8 lenses.

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So from thse two quotes one can easily infer that the 40D has an AF system 1.3X faster than the 400D and with superior AF performance at the outer focus points with lenses of f/5.6 and faster.

However, I have recently come to learn just how critical it is to track a moving target accurately when attempting BIF with my 50D and it is simply not good enough to wave the camera close to the subject. I look at some of your images and see that you have cropped them, so it is impossible to tell the original composition or where your focus point(s?) might be. When shooting with a shallow DOF I imagine it makes a significant difference to the results depending on whereabouts on the rider you have your focus point. It is also worth noting that, even with the 1D3, Canon's advice is to track your subject for around one second to let the AI Servogets its predictive focusing homed in accurately. I imagine a Rebel would benefit from at least as long. Apart from accuracy of aim there is also the matter of what you aim at, how well lit it is and how contrasty.

Before spending money it may be worth trying to borrow a body from the 40D/50D or 1 series range. Alternatively, if you can practice just shooting moving vehicles maybe you can determine whether the kit does have the capability but, unfortunately, you need to work on your targetting skills. e.g. if we take a look at this image....

http://appelflap.ocp-s.tudelft.nl/gallery/index.php/Wielrennen/WTOS/(2009-06-24)%20WTOS%2010km/10km2009june010.JPG

I can see the potential for quite different results depending on whether the focus point was over the hands, the upper arms, or the deep black abyss of the torso, which would have had any AF sustem completely lost, I would think.

So, my advice would be to check out your technique first of all, since without that a "better" body may not help that much, but if your technique is solid I guess you would reap benefits from a body upgrade.

EDIT : I just tried searching for "Canon's fastest focusing lens" and came across this post on POTN - http://photography-on-the.net/forum/showpost.php?p=176616&postcount=5. It's an old post but interesting that the 300/4 is claimed to be slower to focus than the 400/5.6, yet the 300/2.8 is the fastest lens in Canon's lineup. That mixes things up a bit. Nonetheless, I suspect you should tackle the issue in this sequence....

- Check/improve technique (free);
- Upgrade body (not monstrously expensive);
- Upgrade lens (but to what, and at what cost?)

tdodd said:

Pushing up the ISO can't make an f/4 lens focus like an f/2.8 lens. f/2.8 is a significant cutoff point in AF speed and accuracy. According to documentation I've seen, at f/2.8 and faster a camera should be able to focus to within 1/3 DOF. Slower than f/2.8 the AF is only specced to an accuracy of "somewhere" within the DOF.

At a distance of 20m a 300mm f/2.8 lens at f/2.8 will give you a DOF of +/-23cm. The focus accuracy should be off by no more than 7-8cm, pretty much guaranteeing a sharp subject and a safe margin both in front of and behind the focused point.

At a distance of 20m a 300mm f/4 lens at f/4 will give you a DOF of +/-33cm. Your focus could be off by as much as 33cm, meaning a significant portion of your subject may be completely outside the DOF, even if the area you focused on is still within the DOF.

If you used the f/2.8 lens stopped down to f/4 you would gain the f/2.8 AF precision of +/- 7cm and still benefit from the larger DOF of +/-33cm that f/4 offers.

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DOF is quite an interesting subject and reading through the posts you do learn a little each time. I found these two websites that might be useful to
others as well as me on DOF, its got a DOF calculator for camera type, aperture, lens focal length and Focus distance. which is very handy.

http://www.cambridgeincolour.com/tutorials/depth-of-field.htm

http://www.dofmaster.com/dofjs.html

Some good info here.
The upgrade to a pro body and the quality of the backgrounds will make the biggest difference to your number of "keepers". Busy, dark backgrounds tend to confuse the AF on even the best camera. Hazy, low light has a similar effect. I get many more "keepers" in winter, due to the quality of the light , than in summer. My upgrade from D2x to D3 improved the "quality" of my action photos more than any other change I've made.
If you can only do one thing, upgrade your body, as f4 to f2.8 is not as big a deal.
Neil.

300mm 2.8 lens.

Having bought the 300mm 2.8 last year, I found that last winter I got shots in low light that I could never have got with my 100/400 is 5.6 zoom.

Neil said:

If you can only do one thing, upgrade your body, as f4 to f2.8 is not as big a deal.
Neil.

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I assume your are thinking about the better AF sytem on Pro bodies Neil, don't know about Nikon but on Canon's it seems that the AF sytem is one of the main reasons to upgrade to a pro body as far as the bird photographer is concerned.

Mind you I would have thought that a f2.8 lens should help quite a bit with AF as it lets in twice as much light as a f4, trouble is that using a converter (especially a 2x) on the 300/2.8 would negate this advantage if you are only using a 1.4tc on the f4 lens.

All this is just an assumption on my part as I do not own a Pro body or a f2.8 telephoto lens :C